Ten thousand years ago, humans and fairies fought a great battle for the magical island of Ireland. When it became clear to the fairy families that they could never win, they decided to move their civilization underground and keep themselves hidden from the humans. All the fairy families agreed on this, except the 8th family, the demons. The demons planned to lift their small island out of time until they had regrouped and were ready to wage war on...

In the late nineteenth century, when Conor Broekhart discovers a conspiracy to overthrow the king, he is branded a traitor, imprisoned, and forced to mine for diamonds under brutal conditions while he plans a daring escape from Little Saltee prison by way of a flying machine that he must design, build, and, hardest of all, trust to carry him to safety.